What is metadata?

Metadata, also known as intermediary data and relay data, is data that describes data (data about data).

The functions of metadata are:

1. Information describing data attributes (property), used to support functions such as indicating storage location, historical data, resource search, file recording, etc.

2. Metadata is a kind of electronic catalog. In order to achieve the purpose of cataloging, it must describe and collect the content or characteristics of the data, thereby achieving the purpose of assisting data retrieval.

Examples of metadata application:

1. Data structure: name, relationship, field, constraints, etc. of the data set;

2. Data deployment: data The physical location of the set;

3. Data flow: process dependencies between data sets (non-referential dependencies), including rules from one data set to another data set;

4 , Quality measurement: a measurement that can be calculated on the data set;

5. Measurement logic relationship: the logical operation relationship between the data set measurement;

6. ETL process: the process operation Sequential, parallel, serial;

7. Data set snapshot: the distribution of data across all data sets at a point in time.

Extended information:

Advantages of metadata:

1. Self-description: Metadata automatically provides the function of IDL in COM, allowing a file to be used simultaneously in definition and implementation. Runtime modules and assemblies do not even need to be registered with the operating system. As a result, the instructions used by the runtime always reflect the actual code in the compiled file, improving application reliability.

2. Design: Metadata provides all the necessary information about the compiled code for users to inherit classes from PE files written in different languages. Users can create instances of any class written in any managed language (any language that targets a public language runtime) without worrying about explicit marshaling or using custom interoperability code.